Chair arm



FIG. 1 is a perspective view of a chair arm, showing my new design, the broken lines are for environmental purposes only and forms no part of the claimed design;

FIG. 2 is a front elevation view of the left arm thereof;

FIG. 3 is an outside elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is an inside elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The corresponding views of the right arm are the mirror images of the left arm as shown. 

The ornamental design for a chair arm, as shown and described. 